San Francisco Mayor Ed Lee speaks during a press conference updating plans for the 2016 Superbowl held by the San Francisco Bay Area Super Bowl 50 Host Committee in the Kanbar Forum at the Exploratorium on Thursday June 5, 2014 in San Francisco, Calif.

Bay Area companies have pledged $40 million so far to make sure Super Bowl 50 in Santa Clara - now 20 months away - boosts the local economy and showcases the region to the millions of people watching around the world, organizers said Thursday.

Apple, Google, Yahoo, Intel and other companies are partnering with the host committee as it gears up for the golden anniversary of the world's biggest game, which came to the Bay Area just once before - in 1985, when the 49ers beat the Dolphins at Stanford Stadium.

While some 70,000 people are expected to pack into the new Levi's Stadium on Feb. 7, 2016, many more will flood the region - and especially San Francisco - in the days leading up to the big game, attending an estimated 200 parties and events from the Wine Country to Monterey Bay.

San Francisco Mayor Ed Lee has predicted "hundreds of millions of dollars" in economic activity for his city, even though the game will be played 50 miles to the southeast. The 2013 Super Bowl in New Orleans brought $480 million in economic activity to that region, according to one study.

"We want to build the most exciting, innovative, but also philanthropic Super Bowl," Lee said Thursday at a press event at the Exploratorium on Pier 15.

The NFL requires Super Bowl hosts to give at least $1 million to charity, which the league matches, but the Bay Area is going further, organizers said, pledging 25 percent of the money raised from sponsors to nonprofits and impoverished families.

Officials said the goal was to redefine the event by highlighting the Bay Area's people and cultures.

"We're proud of our heritage, our irreverence, and our sense of community," said Daniel Lurie, who headed the group that secured the bid for the Super Bowl one year ago. "We want to shed a light on what is so great about our region. We want every group to be on full display."

The hosting committee also introduced its logo for Super Bowl 50, which looks like a commemorative gold coin and features the Golden Gate Bridge and rays of sunlight meant to represent innovation.

The unveiling came a day after the NFL announced it would for the first time ditch the traditional Roman numerals for the 50th Super Bowl, using "50" rather than "L," saying it was more pleasing to the eye. Many observers noted that "L" is the universal designation for "loser."

Officials around the Bay Area are working on transportation and lodging plans to accommodate the surge of Super Bowl fans. While the game will be played in Santa Clara, much of the fanfare before the kickoff will be in San Francisco - including The NFL Experience, pro football's annual hands-on Super Bowl convention, set for the Moscone Center.

Lurie said that while most official events will take place between San Francisco and Santa Clara, "The entire region will be hosting parties."